This invention relates to submersible pumps and the like, in particular the deployment and retrieval of semi-permanent assemblies into wells and pipelines, especially electrically powered assemblies such as electric submersible pumps (ESPs) and flow regulators based on permanent magnet brushless motors.
A conventional electrical submersible pump installation for oil wells is deployed at the end of a production tubing, the tubing being used to conduct the pumped fluids to surface. The tubing consists of jointed sections, to which the electrical power cable is externally strapped. The motor and centrifugal or positive displacement pump are assembled at the bottom of the tubing, normally with the pump above the motor, so it can lift fluids via a discharge head directly into the tubing.
The ESP must be maintained from time to time. This requires a so-called work-over rig and crew which can pull up and dismantle the sections of tubing from the well and detach the cable to retrieve the pump. The repaired or replaced pump is deployed back into the well as for a new installation, re-making the tubing and affixing the cable. Since there is a high likelihood of damaging the cable and its connectors, these are often replaced during the work-over. This type of work-over is a time consuming and expensive exercise, and it is often done to a fixed schedule that leaves failed installations until the next scheduled slot, with consequent lengthy periods without production.
An alternative known method of ESP installation disclosed in GB 2 318 167 uses coiled tubing. In this the power cable is pre-installed into the continuous tubing and makes on to the motor, which is now above the pump. The fluids are lifted in the annulus between the tubing and the well casing. Since the ESP is reeled into and out of the well, work-over costs are significantly reduced compared to the conventional means of installation. Nevertheless the method requires the use of a reeled tubing rig and remains expensive.
It is an objective of this invention to allow convenient recovery of components disposed in a well or pipeline.
According to the present invention, there is provided an oil flow line and powered device system comprising:
a tube for the transportation of oil, and
at least one powered device, the powered device being disposable in the tube,
the tube having an electrical power transmission means disposed along at least some of its length,
the tube having a first power transfer means, and the powered device having a second power transfer means, the first power transfer means and second transfer means being capable of co-operating so as to transfer power from one to the other.
Preferably the first power transfer means act as a stator of a motor, and the second power transfer means act as a rotor of a motor.
Preferably the inner surface of the tube includes at least one locating means for locating the powered device at a particular position in the tube
Alternatively or additionally the powered device includes a gripping means to secure itself to the inner surface of a tube.
According to another aspect of the present invention, there is provided a method of delivering or retrieving a powered device in a powered device and flow line system oil flow line and powered device system comprising:
a tube for the transportation of oil, and
at least one powered device, the powered device being disposable in the tube,
the tube having an electrical power transmission means disposed along at least some of its length,
the tube having a first power transfer means, and the powered device having a second power transfer means, the first power transfer means and second transfer means being capable of co-operating so as to transfer power from one to the other,
including the step of applying fluid pressure to the flow line.
According to another aspect of the present invention, there is provided a method of delivering or retrieving a powered device in a powered device and flow line system comprising:
a tube for the transportation of oil, and
at least one powered device, the powered device being disposable in the tube,
the tube having an electrical power transmission means disposed along at least some of its length,
the tube having a first power transfer means, and the powered device having a second power transfer means, the first power transfer means and second transfer means being capable of co-operating so as to transfer power from one to the other,
including the step of operating a traction means to interact between the tube and the powered device.
According to a further aspect of the present invention, there is provided a tube for an oil flow line and powered device system the oil flow line and powered device system comprising:
a tube for the transportation of oil, and
at least one powered device, the powered device being disposable in the tube, the tube having an electrical power transmission means disposed along at least some of its length,
the tube having a first power transfer means, and the powered device having a second power transfer means, the first power transfer means and second transfer means being capable of co-operating so as to transfer power from one to the other.
According to a further aspect of the present invention, there is provided a powered device for an oil flow line and powered device system the oil flow line and powered device system comprising:
a tube for the transportation of oil, and
at least one powered device, the powered device being disposable in the tube,
the tube having an electrical power transmission means disposed along at least some of its length,
the tube having a first power transfer means, and the powered device having a second power transfer means, the first power transfer means and second transfer means being capable of co-operating so as to transfer power from one to the other.
The powered device may include a traction means which interacts between the tube and the powered device so as move the powered device along the flow line.
It is a further objective of this invention that said docking ports be addressable when required to permit individual control.
In this way, the electrical power cable, its connectors, and production tubing remains in the well during an entire ESP work-over. Docking ports are used to station and operate modular pumps, valves, sensors and/or other actuators at one or more locations, said docking ports possibly being addressable when required to permit individual control.
The modules may be recovered by the production fluids themselves as an alternative or in addition to special hydraulic fluids. These modules are recovered by re-circulating the said fluids using a permanent flow path in or attached to the production tubing. The modules are also recoverable by a wireline or slickline operation for back-up or primary means of recovery, and by electric powered traction tools.
Electrical connections between said modules and docking ports are not required. Rotary or linear motor action be developed using stator coils mounted in or on the fixed part of the downhole assembly and permanent magnets mounted in or on the said modules. The said modules may be individually controlled from the same power supply.